Aerobic exercise is a popular form of exercise that improves one's cardiovascular health by reducing blood pressure and providing other benefits to the human body. Aerobic exercise generally involves low intensity physical exertion over a long duration of time. Generally, the human body can adequately supply enough oxygen to meet the body's demands at the intensity levels involved with aerobic exercise. Popular forms of aerobic exercise include running, jogging, swimming, and cycling among others activities. In contrast, anaerobic exercise often involves high intensity exercises over a short duration of time. Popular forms of anaerobic exercise include strength training and short distance running.
Many choose to perform aerobic exercises indoors, such as in a gym or their home. Often, a user will use an aerobic exercise machine to have an aerobic workout indoors. One such type of aerobic exercise machine is an elliptical exercise machine, which often includes foot supports that move in fixed reciprocating directions when moved by the feet of a user. Often, the foot supports will be mechanically linked to arm levers that can be held by the user during the workout. The arm levers and foot supports move together and collectively provide resistance against the user's motion during the user's workout. Other popular exercise machines that allow a user to perform aerobic exercises indoors include treadmills, rowing machines, stepper machines, and stationary bikes to name a few.
One type of exercise device is disclosed in U.S. Pat. No. 5,993,359 issued to Paul Eschenbach, et al. In this reference, a standup cross trainer exercise apparatus simulates walking and jogging, having separately supported pedals for the feet and arm exercise, coordinated with the motion of the feet. Foot pedals move with a back and forth movement following an elongate curve path that has adjustable curve length during operation. The stride length of the foot pedals is adjustable to accommodate both long and short leg users. Foot pedals move with smooth elliptical motion resulting from a linkage mechanism having smooth orbital motion without the characteristic turnaround jerk associated with reciprocating member elliptical drives. Arm exercise in the disclosed reference is coordinated with the motion of the feet and adjusts with longer or shorter pedal strides to accommodate taller or shorter users. Other types of exercise machines are disclosed in U.S. Pat. No. 6,422,977 issued to Paul Eschenbach, et al. and U.S. Pat. No. 7,468,021 issued to Daniel R. Moon; and in U.S. Patent Publication No. 2007/0054779 issued to Lung-huei Lee. All of these references are herein incorporated by reference for all that they contain.